v86

Building

See docker/test-image/Dockerfile for a full setup on Debian.

You need:

• java
• gcc, make, libc-i386
• nasm, gdb and qemu (for running tests)
• rust-nightly with the wasm32-unknown-unknown target
• nodejs (a latest version is required, 10.11.0 is known to be working)

Run make all-debug to build the debug build (at debug.html). Run make all to build the optimized build (at index.html).

Testing

Run all tests: make jshint rustfmt kvm-unit-test nasmtests nasmtests-force-jit expect-tests jitpagingtests qemutests rust-test tests

Creating a Linux image for use in v86

See docker/debian-full/Readme.md.

Below is the readme of the open-source version of v86 (not everything applies)

API examples

• Basic
• Programatically using the serial terminal
• A Lua interpreter
• Two instances in one window
• Saving and restoring emulator state

Using v86 for your own purposes is as easy as:

var emulator = new V86Starter({
    screen_container: document.getElementById("screen_container"),
    bios: {
        url: "../../bios/seabios.bin",
    },
    vga_bios: {
        url: "../../bios/vgabios.bin",
    },
    cdrom: {
        url: "../../images/linux.iso",
    },
    autostart: true,
});

See API.

How does it work?

v86 emulates an x86-compatible CPU and hardware. Here's a list of emulated hardware:

• An x86 compatible CPU. The instruction set is around Pentium 1 level. Some features are missing, more specifically:
  • Task gates, far calls in protected mode
  • 16 bit protected mode features
  • Single stepping
  • MMX, SSE
  • A bunch of FPU instructions
  • Some exceptions
• A floating point unit (FPU). Calculations are done with JavaScript's double precision numbers (64 bit), so they are not as precise as calculations on a real FPU (80 bit).
• A floppy disk controller (8272A).
• An 8042 Keyboard Controller, PS2. With mouse support.
• An 8254 Programmable Interval Timer (PIT).
• An 8259 Programmable Interrupt Controller (PIC).
• A CMOS Real Time Clock (RTC).
• A VGA controller with SVGA support and Bochs VBE Extensions.
• A PCI bus. This one is partly incomplete and not used by every device.
• An IDE disk controller.
• An NE2000 (8390) PCI network card.
• A virtio filesystem.

Testing

The disk images are not included in this repository. You can download them directly from the website using:

wget -P images/ https://copy.sh/v86/images/{linux.iso,linux3.iso,kolibri.img,windows101.img,os8.dsk,freedos722.img,openbsd.img}.

A testsuite is available in tests/full/. Run it using node tests/full/run.js.

How to build, run and embed?

• Building is only necessary for releases, open debug.html and everything should load out of the box
• If you want a compressed and fast (i.e. with debug code removed) version, you need Closure Compiler. Download it as shown below and run make build/v86_all.js.
• ROM and disk images are loaded via XHR, so if you want to try out index.html locally, make sure to serve it from a local webserver. You can use make run to serve the files using Python's SimpleHTTPServer.
• If you only want to embed v86 in a webpage you can use libv86.js. For usage, check out the API and examples.
• A couple of disk images are provided for testing. You can check them out using wget -P images/ https://copy.sh/v86/images/{linux.iso,linux3.iso,kolibri.img,windows101.img,os8.dsk,freedos722.img,openbsd.img}.

Short summary:

# grab the main repo
git clone https://github.com/copy/v86.git && cd v86

# grab the disk images
wget -P images/ https://copy.sh/v86/images/{linux.iso,linux3.iso,kolibri.img,windows101.img,os8.dsk,freedos722.img,openbsd.img}

# grab closure compiler
wget -P closure-compiler https://dl.google.com/closure-compiler/compiler-latest.zip
unzip -d closure-compiler closure-compiler/compiler-latest.zip *.jar

# build the library
make build/libv86.js

# run the tests
./tests/full/run.js

Compatibility

Here's an overview of the operating systems supported in v86:

• Linux works pretty well. Graphical boot fails in many versions, but you mostly get a shell. The mouse is often not detected automatically.
  • Damn Small Linux (2.4 Kernel): Works, takes circa 10 minutes to boot.
  • Tinycore (3.0 kernel): udev and X fail, but you get a terminal.
  • Nanolinux works.
  • Archlinux works with some caveats. See archlinux.md.
• ReactOS works
• FreeDOS, Windows 1.01 and MS-DOS run very well.
• KolibriOS works. A few applications need SSE.
• Haiku boots, but takes very long (around 30 minutes).
• No Android version seems to work, you still get a shell.
• Windows 1, 95 and 98 work. Other versions currently don't.
• Many hobby operating systems work.
• FreeBSD works

You can get some infos on the disk images here: https://github.com/copy/images.

How can I contribute?

• Add new features (hardware devices, fill holes in the CPU), fix bugs. Check out the issues section and contact me if you need help.
• Report bugs.
• If you want to donate, let me know.

License

Simplified BSD License, see LICENSE, unless otherwise noted.

Credits

• CPU test cases via QEMU, http://wiki.qemu.org/Main_Page
• More tests via kvm-unit-tests
• Disk Images
• The jor1k project for 9p, filesystem and uart drivers
• WinWorld sources of some old operating systems

More questions?

Shoot me an email to copy@copy.sh. Please don't tell about bugs via mail, create a bug report on GitHub instead.

Author

Fabian Hemmer (http://copy.sh/, copy@copy.sh)